Disclosed herein is an apparatus and method that controls fuser nip balance.
Presently, image output devices, such as printers, multifunction media devices, xerographic machines, ink jet printers, and other devices, produce images on media sheets, such as paper, substrates, transparencies, plastic, cardboard, or other media sheets. To produce an image, marking material, such as toner, ink jet ink, or other marking material, is applied to a media sheet to create a latent image on the media sheet. A fuser assembly then affixes or fuses the latent image to the media sheet by applying heat and/or pressure to the media sheet.
Fuser assemblies apply pressure using rotational members, such as fuser rolls or belts, that are coupled to each other at a fuser nip. Pressure is applied to the latent image on the media sheet as the media sheet is fed through the fuser nip. A single cam shaft mechanism applies force to one fuser member to generate the pressure against the other fuser member at the fuser nip. A single shaft cam mechanism, with an actuator motor and sensors for cam in and out positions, is used to load the fuser nip. In an edge registered system, pressure roll flare, used for wrinkle control, is non-symmetric across the length of the roll. Unfortunately, the pressure roll flare results in an unbalanced nip for all but the widest paper sizes. The unbalanced nip results in shortened fuser roll life and increased gloss variation on the final image.
Thus, there is a need for an apparatus and method that controls fuser nip balance.